Reciprocal electromechanical properties of rat prestin:: The motor molecule from rat outer hair cells
Reciprocal electromechanical properties of rat prestin:: The motor molecule from rat outer hair cells
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DOI：
10.1073/pnas.071613498
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发表时间：
2001-03-27
影响因子：
11.1
通讯作者：
Fakler, B
中科院分区：
文献类型：
--
作者：
Ludwig, J;Oliver, D;Fakler, B
耳蜗外毛细胞（OHCs）是哺乳动物听觉器官中具有灵敏、动态范围和分辨频率能力的细胞。这些独特的细胞对电刺激的反应是细胞长度的周期性变化，这种变化是由细胞基底膜上的分子马达介导的。最近的研究发现，prestin是一种与penddrin相关的阴离子转运蛋白相似的蛋白质，是OHC的运动分子。本研究表明，从大鼠OHC中异种表达的prestin （rprestin）表现出与OHC马达蛋白相同的互易机电特性。在微室结构中进行电刺激后，抑制素产生恒定振幅和相位的机械力，刺激频率至少为20khz。在切除的外向斑块中对抑制素进行机械刺激，改变了表征分子电性能的非线性电容的电压依赖性。结果表明，抑制素是一种分子马达，在与哺乳动物听力相关的整个频率范围内表现出互反的机电特性。
Cochlear outer hair cells (OHCs) are responsible for the exquisite sensitivity, dynamic range, and frequency-resolving capacity of the mammalian hearing organ, These unique cells respond to an electrical stimulus with a cycle-by-cycle change in cell length that is mediated by molecular motors in the cells' basolateral membrane. Recent work identified prestin, a protein with similarity to pendrin-related anion transporters, as the OHC motor molecule. Here we show that heterologously expressed prestin from rat OHCs (rprestin) exhibits reciprocal electromechanical properties as known for the OHC motor protein. Upon electrical stimulation in the microchamber configuration, rprestin generates mechanical force with constant amplitude and phase up to a stimulus frequency of at least 20 kHz, Mechanical stimulation of rprestin in excised outside-out patches shifts the voltage dependence of the nonlinear capacitance characterizing the electrical properties of the molecule. The results indicate that rprestin is a molecular motor that displays reciprocal electromechanical properties over the entire frequency range relevant for mammalian hearing.